Version: (using KDE 3.5.7 "release 64.1" , openSUSE ) Compiler: Target: i586-suse-linux OS: Linux (i686) release 2.6.16.27-0.9-default There are multiple use cases for changing window parameters when a program is already running: starting an app in the background at login kstart --skiptaskbar --iconify -windowclass "kontact" "kontact" and making it visible later on would zero the startup time for any desired app: kstart --activate --currentdesktop -windowclass "kontact" --allinstances/-pid 23507 (At the moment this prog. needs up to 15s to start) other use cases: changing xinerama screen: Bug 140559, Bug 148708
I don't think it is possible to affect running applications with kstart as kstart uses a hack that involves it first launching the application. Are you talking about changing the window parameters as a user or using scripting? As a user, just use KWin's window-specific settings (Alt+F3/Advanced), there it's possible also to only apply the change at the moment. For scripting, see e.g. http://www.kde-apps.org/content/show.php?content=40425 or http://www.sweb.cz/tripie/utils/wmctrl/ .